Simple Machines and Efficiency

How can you decrease the effort force needed to push a weight to the top of the ramp? 

• cover the surface with carpet
• increase the length of the ramp
• increase the height of the ramp
• decrease the length of the ramp

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NGSS.MS-PS2-2

How does a single fixed puled, like the one seen here, help you do work?

• changes the direction of the force
• increases the amount of applied force
• decreases the amount of applied force
• allows you to pull the rope a shorter distance

Barbie sits on one end of a see-saw and Ken sits on the other. Barbie goes up in the air and Ken stays down on the ground. In order for Ken to make Barbie move down, he should

• stand on the board
• push down on the board
• move towards the center
• move away from the center

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NGSS.MS-PS2-4

The amount by which a machine multiplies input force is known as the 

• work.
• power.
• output force.
• mechanical advantage.

A 62 kg box is lifted 12 m off the ground. How much work was done? (hint: calculate F_w first)

• 5.17 J
• 72.91 J
• 744.0 J 
• 7291.2 J

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NGSS.MS-PS2-2

NGSS.MS-PS2-4

Mechanical advantage is a measure of how much a machine multiplies the input

• efficiency.
• force.
• power.
• work.

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NGSS.MS-ETS1-1

Calculate the amount of work done if you use a 100N force to push a 50 kg box 5 m across the kitchen floor. 

• 250 J 
• 500 J
• 5000 J
• 50,000 J

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NGSS.HS-PS3-1

What is the primary mechanical advantage of using the simple machine seen in the image?

• You can apply a large force and have it penetrate over a very long distance.
• You can apply a long distance and have it convert into a very short distance.
• You can apply a short distance and have it multiplied to penetrate a large distance.
• You can apply a small force to penetrate something that normally requires a large force.

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NGSS.MS-PS2-1

Jeff is a landscaping contractor and lifts a rock weighing 600 pounds by wedging a board under the rock. Jeff weighs 150 pounds and puts all of his weight on the lever. How much mechanical advantage did the lever provide to Jeff in lifting the rock?

• 0
• 2
• 4
• 8

A screwdriver is an example of a wheel and axle, which is a type of simple machine. The mechanical advantage of a wheel and axle is the ratio of the radius of the wheel to the radius of the axle. The force required to turn a screw can be reduced by

• reducing the length of the axle.
• increasing the radius of the axle.
• reducing the length of the handle.
• increasing the radius of the handle.

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NGSS.MS-PS2-2